A couple days into their first spring minicamp, the Eagles’ skill guys are raving about the unique offensive system Kelly brought to Philly from Oregon.

Once upon a time, Andy Reid’s West Coast Offense was considered cutting edge. As recently as 2010, the Eagles were No. 3 in the NFL in scoring.

Now Kelly brings in a system of communicating plays and running offense that the players say has never been attempted before.

“From a communications standpoint, it’s going to change the league,” Celek said. “I’m not going to tell you guys how, but it will. Just the way that they can communicate plays in and get us the stuff, it’s pretty cool. It’s something that I never even thought was possible in the NFL.

“And then seeing the stuff he’s doing, he has a reason why he does everything that he does and a reason why each play is called what it is, and it all makes sense.”

Whether Kelly’s coaches on the sideline will use a system of hand signals or play cards or Semaphore flags to relay plays to the guys on the field in his no-huddle offense remains to be seen.

Whether it will be successful remains to be seen.

But it will be different. So far, that’s really all we know.

“I can’t say that we’re going to be super successful, but from a communications standpoint, yeah, it’s insane,” Celek said. “There is a reason why he calls everything the way he calls it. it’s pretty cool. it’s all thought out to the Nth degree.”

Although the Eagles have shaken up the defense to a great extent during the offseason, getting rid of Nnamdi Asomugha, Cullen Jenkins, Mike Patterson, Dominique Rodgers-Cromartie, Akeem Jordan and Darryl Tapp, among others, the offense is fairly intact.

In fact, everybody who caught a pass or had a carry for the 2012 Eagles with the exception of Stanley Havili and Dion Lewis is still on the roster, along with both quarterbacks, Michael Vick and Nick Foles.

So everybody is learning together.

"The hardest thing is unlearning everything you know,” Avant said. “Deleting the old software and installing the new software.”

So what do we know so far?

The Eagles want to run a play 12 seconds after the last play ends. They’ll use a unique way to wig-wag plays from the sideline to the field. They’ll practice at a faster pace than any other NFL team. Skill guys will have some measure of freedom in the routes they run in some situations. We’ll see lots of tight ends and no fullbacks.

“Everything’s going to be fast, obviously, but he has a lot of different ways to put people in position to be successful, so I’m excited to see this offense evolve,” Maclin said. “I have no idea what else he has for us.

“I think it’s going to be exciting, and I think we’ll have guys in position to make plays. It’s a little different, but at the end of the day, it’s still football. You still have to run and catch and tackle, but at the same time we’re all new in this thing.”

It worked at Oregon, where Kelly went 46-7 in four years and 36-4 the last three years.

Kelly’s Ducks averaged 44.9 points from 2009 through 2012 and scored 40 or more points in 40 of his 53 games as a head coach. They put up 50 or more 19 times, 60 or more seven or more times, 70 or more twice.

The system works. But will it work here?

“It’s definitely different,” Avant said. “It’s going to take us a little while to adjust to the plays, knowing when you can improvise and when you can’t. Those type of nuances will take a little while, but coach Chip’s offense is definitely new, and we’re excited about some of the great ideas that he has.”

During Reid’s tenure, the Eagles averaged 23 points per game, seventh-most in the NFL from 1999 through 2012.

Now it’s time for something else. A new scheme, a new philosophy, a new way to practice. New everything.

“It’s different,” Celek said. “You’re so used to Coach Reid for so long. Even growing up I saw Coach Reid as the figure of Philadelphia. But things change, and I love what Coach Kelly has brought.”